1. Field of the Invention
The present invention relates to an apparatus for recording and reproducing information.
2. Related Background Art
Hitherto, various kinds of disc-shaped medium, card-shaped medium, and the like have been known as forms of media to record information using a light and to read out the recorded information. Among them, the cardshaped optical information recording medium (hereinafter, referred to as an optical card) is a small and light weight portable medium having a large recording capacity.
An apparatus for recording and reproducing information into/from the foregoing optical card, is disclosed in U.S. Application No. 810,747.
FIG. 3 is a schematic plan view of an optical card, in which reference numeral 101 denotes a recording medium, 106 (106a106b, . . .) indicates an information track, and 321 (321a, 321b, 321c, 321d, . . .) represents a directory.
In the foregoing optical card, information is recorded as a recording pit train (information track) which can be optically detected by scanning the card by use of a laser beam modulated in accordance with recording information and focused a microspot.
Due to the popularity of the optical card, the optical card is used in various kinds of applications. However, in this case, the optical card needs to be protected when it is used in a different application, namely, the recording and reproducing operation needs to be disabled. In general, in such a case, an ID (identification) code is preliminarily recorded in the data section and when the ID code input by the user does not coincide with the recorded ID code, the medium used in the different system is not accepted. However, such a protection is not executed in the recording and reproducing apparatus but, in general, it is executed in a host control unit (on the side of a host computer) which is connected to this apparatus.
Therefore, a problem hardly occurs when the ordinary user cannot operate the host control unit as in the case of a card system of a bank. However, in the case of a system such that the host control unit uses a personal computer, the user can relatively easily examine the ID code and the like, so that there is a danger such that the protection is easily broken.